Self-Reported Knee Function, Pain Worse Than Doc-Assessed

FRIDAY, Oct. 28 (HealthDay News) -- Following total knee arthroplasty, self-reported American Knee Society pain and function subscores are worse than clinician-assessed scores, but self- and clinician-assessment of the Oxford Knee Score is similar, according to a study published in the Oct. 19 issue of the Journal of Bone and Joint Surgery.

Gaurav Khanna, M.D., from the University of Minnesota Medical School in Minneapolis, and colleagues compared clinician-assessed values with patient self-reported measures to identify whether patients could reliably assess their own outcome using the American Knee Society Score and Oxford Knee Score questionnaires, and self-reported knee motion. A total of 140 patients (with 181 affected knees) were mailed questionnaires, a set of photographs illustrating knee motion in 5 degree increments for comparison with their range of knee motion, and a goniometer with instructions. Within two weeks of the self-evaluation, the patient's American Knee Society Score, Oxford Knee Score, and knee motion were independently assessed by one of three clinicians.

The investigators found that, compared with the clinically-assessed score, the mean patient-reported American Knee Society pain and function subscores were four and 10 points worse, respectively. There were no significant differences between the patient-reported and clinician-assessed mean Oxford Knee Score (P = 0.05). There was less than a 1 degree difference in the mean maximum flexion reported by the patient with use of the photographs and the mean value reported with use of the goniometer, or from the mean value measured by the clinician, but there was no clinical relevance to these differences.

"Patients' self-reported American Knee Society pain and function subscores were worse than the corresponding clinician assessments, but the two Oxford Knee Scores were similar," the authors write.

One or more of the study authors disclosed financial ties to the biomedical industry.